Funny idle after tappet adjustment

[EuroDude]

My engine was noisy so I got my tappets adjusted yesterday.

The problem is that when the engine is idling, I can feel very faint "kicks" or "dips" from the engine randomly (maybe once or twice a second). The faint kick/dips are like when the car idle is a bit too low and the car has trouble staying alive.

There is no lack of performance, the car has actually increased throttle responce considerably. And the engine does not bog out or anything.

When the AC is on, I dont really notice it, but then again - AC causes the engine to constantly dip anyway due to the extra load


:confused: The thing is, the mech was adjusting one of the tappets, and it fell off the mushroom(?) into the engine. He got the tappet out and had to jam the flat part back into the valve top with a screwdriver then adjusted it to spec, but there didnt appear to be any damage from what I could see.


Theory 1:
The tappet has been slightly damaged or something, causing intermittent cylinder performance loss.

Theory 2:
Does adjusting the tappets bring the idle down a bit? (but wouldnt it go up?). I am guessing that the idle has lowered a bit and the car is kindof hesitating during idle. But I dont really notice any idle RPM loss. btw my tachometer isnt very accurate and sometimes sticks near 1100rpm even though its lower (I have put on an aftermarket cluster face), so I cant compare before-and-after RPM's.



Any ideas?

[hotrat]

Valve adjustment shouldnt cause that so long as they are adjusted properly, it may make the engine run smoother but the idle should still be set by the ecu, so any change in the engine should be compensated for by the "brain" and adjusted accordingly, more likely that one of the vaccum lines or hoses is leaking, or a wire is pinched, something likely caused by the fact that the valve cover was removed. Just a guess but thats what I would look at, or just take it back to the mechanic aand make him deal with it.

[bennjamin]

i just hope that mech waited for the engine to be prety much stone cold before re-adjusting the clearances. I bet one or more rocker arms is too tight or too loose.

EDIT as said below - check spark plugs , spark plug leads - and even look at your distributor might be on the way out ( coil unit or igniter module etc)

[SINISTR]

im thinking its your spark plugs mate - my car does it too when the plugs are getting old. before you may not have noticed as everything else was something you were used to, now you've eliminated a substential part of the noise and the way the motor works... there is something else thats bound to 'sound or feel different' I think its your plugs.

[HyperZ]

Try cleaning the IACV? Theres a DIY thread if u do a search. Reset the ECU may help?

[riceball]

reset your ecu.

[EuroDude]

Thx for the feedback.

Spark Plugs are only a week old
Spark leeds are a few months old
IACV is clean
FITV is screwed in
Throttle body is clean
Dizzy coil is new, Dizzy cap is new.
Dizzy Igniter is still original I think, but I dont think its that.
All wires and pipes seem ok.


The thing is, the engine was perfectly fine prior to the tappet adjustment.

I will try and reset the ECU first. Is this how its done?:
1) Disconnect the Negative Battery terminal
2) Remove the Backup fuse
3) Leave it out for 2 minutes
4) Plug the fuse, then the neg batt term
?

@Ben I think you may be right, the engine was very warm when the mech worked on it, but the mech said he will compensate the temperature by using a thicker spacer/clearance measurement (or whatever you call those things).


I may check the clearances myself when its cold (I watched him do everything :D ) but I need to know some things:

1) What is the recommended tappet clearance for a D16A8?

2) What brand/product of gasket re-sealer do I use? (the black goo you dap in the corners of the head)?

3) Whats the tool I need to rotate the engine to TDC and BDC?

[bennjamin]

@Ben I think you may be right, the engine was very warm when the mech worked on it, but the mech said he will compensate the temperature by using a thicker spacer/clearance measurement (or whatever you call those things).


I may check the clearances myself when its cold (I watched him do everything :D ) but I need to know some things:

1) What is the recommended tappet clearance for a D16A8?

2) What brand/product of gasket re-sealer do I use? (the black goo you dap in the corners of the head)?

3) Whats the tool I need to rotate the engine to TDC and BDC?


check it at first thing in the morning just incase ( sitting overnight etc)
1) the clearance off the top of my head is 0.017-0.019 in/ex.

2)Get some "honda bond" (grey stuff) from honda i guess...or some other sealant stuffl. You only really need it over the grommet area that goes over the camshafts to propery seal.

3) You use a breakerbar/ratchet , a 17mm or 19mm socket piece and a long extension placed on the crank pulley bolt - rotate with the spark plugs OUT and u shoudnt have any probs.

[EuroDude]

Thanks I'll do it on the weekend.

in/ex? The mech used the same spacer for all tappets. Are the exhaust ones supposed to be higher?
I'll google for the proper clearance, unfortunately my Haynes manual only has SOHC engines.

The mech didnt touch the sparkies, are u supposed to remove them?

[bennjamin]

you are supposed to remove the sparkplugs to make it easier to rotate the engine to each cylinder for adjustment ( no spark plug = no compression = easy to turn over.

The measurements for our engine are the same in/ex - Did you see the mech actually turn it over to each correct cylinder and adjust ? (#1 , #3 , #4 , #2 i think it is)

Also - try this handy d16a8/ZC valve adjustment guide...

http://www.thezcr.com/forums/attachment.php?attachmentid=960&d=1115011917

*pdf file

[SINISTR]

Its just easier to turn the crank over with the spark plugs out. I agree that you should check the clearances at a cold engine temp - but with an experienced mechanic it shouldn't be a problem. You'd hear it if you're pinging or tappets are playing up.

Whats your car idling at? because you say its a very faint type of surge but then it feels like its stalling? and its only at idling yeah?

[EuroDude]

Thx for that pdf - its what i was looking for. I'll remove the sparkies first.

No he didnt turn it over four times. First he turned to TDC and then adjusted the 8 wobbly tappets, then he turned it over to 'Bottom Dead Center'(?) and did the other 8 tappets.

Is this wrong? :?

[EuroDude]

Its just easier to turn the crank over with the spark plugs out. I agree that you should check the clearances at a cold engine temp - but with an experienced mechanic it shouldn't be a problem. You'd hear it if you're pinging or tappets are playing up.

Whats your car idling at? because you say its a very faint type of surge but then it feels like its stalling? and its only at idling yeah?


Unfortunately I cannot tell what the exact RPM is. When I put the new cluster face on, the RPM pin came out and its been dodgy ever since (sometimes it sticks at 1000rpm, if I turn up the bass, sometimes it vibrates down to where it should be).


Yeah its only at idle (hot or cold). I felt a very similar surge when my throttle body was dirty (engine was near-stalling). But it kinda feels different this time (its not as harsh as an engine stall). Its more like when the exhaust pops where you hear those faint pops, but in my case I can actually feel the car surge or bump a bit when it pops.

[bennjamin]

Thx for that pdf - its what i was looking for. I'll remove the sparkies first.

No he didnt turn it over four times. First he turned to TDC and then adjusted the 8 wobbly tappets, then he turned it over to 'Bottom Dead Center'(?) and did the other 8 tappets.

Is this wrong? :?

afaik that is wrong - you must get the crank to TDC #1 , adjust those , then turn the crank 180 degrees to #3 , adjust and so on.
Follow that guide and make sure - its a handy DIY which teaches u a thing or two too :)

[SINISTR]

yeah - thats HELL WRONG!!! Im surprised you're not getting any tappet noise...
guess hes not that 'professional' is he... fark!

[EuroDude]

hmm last time he did the tappets that way and they were fine so maybe he knows whats he's doing.

The TDC tappet pattern was something like:
I**--**--
E****----

then 180^

I--**--**
E----****


but then again he may just be taking a dodgy shortcut to same time lol.
Anyway I'll do it the proper way (according to the pdf) to be safe..

[ECU-MAN]

Thx for that pdf - its what i was looking for. I'll remove the sparkies first.

No he didnt turn it over four times. First he turned to TDC and then adjusted the 8 wobbly tappets, then he turned it over to 'Bottom Dead Center'(?) and did the other 8 tappets.

Is this wrong? :?

wrong big time

engine not stone cold, another huge no no.

you really should redo your tappets before you burn out a valve.

http://www.ozhonda.com/forum/showthread.php?t=15443&highlight=tappets

use the above link for an idea of how it should be done, its for SOHC but DOHC is no diff.

[EuroDude]

Well it looks like i need a new mech :confused:
I dont trust him anymore...

Thx all, i'll fix it up myself on Saturday using that DIY and the PDF. :thumbsup:

[EuroDude]

Today I noticed that if I give it some gas, the lower half of the rev range (1000 to 4200RPM) is very powerful (actually more powerful that its ever been believe it or not), but after 4500RPM the engine loses considerable power. My guess is that its getting more fuel/air down low, but less exhaust output up high - thanks to the mucked up clearances.

Usually its the other way around obviously, but yeah anyway i'll drive it like a granny tomorrow till I have time to fix it.

[EuroDude]

It took me 2 hours but I re-adjusted the tappets "properly" and the engine is now running normal - no more phuds or strange power curves :thumbsup:

14 out of 16 tappets were WAY too tight, and the two Intake tappets on Cyl#2 were very loose.

guess if u want something done properly, do it yourself lol

[ECU-MAN]

awsome, you have done well

its sad when you have to do someting like this your self to fix a more experienced persons mistake :confused: